1. Field of the Invention
The present invention relates to a refrigerator, and more particularly to an automatic icemaker which can recirculate a water overflowing from an ice tray to a water reservoir while a water supply cycle is being carried out.
2. Description of the Prior Art
Generally, a refrigerator comprises an automatic icemaker which periodically carries out a water supply cycle for supplying a water to be frozen into an ice tray, an ice making cycle for freezing the water in the ice tray, and an ice removing cycle where the ice tray is reversed by a driving device, an ice formed therein is dropped into an ice receiving container and the ice tray is returned into an initial position.
FIG. 1 shows a perspective view showing a conventional automatic icemaker 100 of a refrigerator. As shown in FIG. 1, automatic icemaker 100 comprises an ice tray 130 for receiving a water to be frozen, an ice receiving container 140 for receiving ice pieces formed in ice tray 130, a water supply device 160 for supplying a water to ice tray 130 and a water supply hose 150. Ice tray 130 is installed at a predetermined position in a freezer compartment 110. In ice tray 130, a plurality of partitions 134 are provided in order to separate an inner space of ice tray 130 into a plurality of subspaces. Ice tray 130 is formed at a center position of one side wall thereof with a rotating shaft 132 integrally extending and being assembled with a driving device(not shown). Ice tray 130 has a box shape, of which an upper portion is opened. Below ice tray 130, ice receiving container 140 is located. While an ice removing cycle is being carried out, ice tray 130 is rotated by the driving device and an ice formed therein is dropped into ice receiving container 140. Ice receiving container 140 has a volume larger than that of ice tray 130 so as to stably receive the ice pieces formed in ice tray 130.
Water supply device 160 is installed at a predetermined position of an upper portion of a refrigerating compartment 120 and comprises a water reservoir 170 for storing a water to be supplied into ice tray 130 and a pump 172 installed at one side of water reservoir 170 for pumping the water stored in water reservoir 170.
Automatic icemaker 100 comprises a water supply hose 150 for guiding the water pumped by pump 172. Water supply hose 150 has a one end connected to pump 172 and an other end extending upward and being located above ice tray 130 so as to communicate with ice tray 130.
Meanwhile, water reservoir 170 is fluidly communicated with a water tank(not shown). A water level of water reservoir 170 is maintained at the same level as a water level of the water tank by a valve(not shown). A water supplying to the water tank is manually carried out.
In conventional automatic icemaker 100 having an above-mentioned structure, the water supplying begins by an actuation of pump 172. When a predetermined amount of water is supplied to ice tray 130, the water supply cycle stops and the ice making cycle starts. At this time, the water in ice tray 130 is frozen so as to form ice pieces. After the water is entirely frozen into the ice pieces, ice tray 130 is rotated by the driving device and the ice pieces fall down into ice receiving container 140. Thereafter, the water supply cycle starts again.
Meanwhile, a temperature detecting sensor 136 is installed at an underside of ice tray 130. If sensor 136 detects a temperature which is lower than a predetermined temperature within a predetermined time after the water supply cycle starts by pump 172, sensor 136 sends an electric signal to an ECU(not shown). At this time, the ECU judges that the water supplying is failed and controls water supply device 160 so as to supply again the water after a predetermined time. If sensor 136 detects that the temperature is below the predetermined temperature within the predetermined time after the water supply cycle starts again, sensor 136 sends an electric signal to the ECU and the ECU judges that there is an error at water supply device 160 and eventually stops automatic icemaker 100.
Water supply device 160 further comprises a water detecting rod 174 to detect an existence of water in water reservoir 170 before the water supply cycle starts. Water detecting rod 174 detects whether a water exists in water reservoir 170 or not, and when it detects that the water does not exist, it sends an electric signal to the ECU. Then the ECU keeps water supply device 160 inactivated and keeps it wait until a water is supplied into water reservoir 170 and the water is detected by water detecting rod 174.
However, as mentioned above, since conventional automatic icemaker 100 is operated only when a water exists in water reservoir 170, an additional circuitry for detecting the existence of the water and accordingly, for controlling icemaker 100, is required. In addition, when a lump of ice in which the ice pieces are connected above upper edges of partition walls 134 in ice tray 130 is formed, the lump of ice is not easily removed, and also in this case, the water is again supplied to ice tray 130, so the water overflows from ice tray 130.
Meanwhile, U.S. Pat. No. 4,848,102 issued to Ted M. Stanfill discloses an automatic icemaker which can circulate the water overflowing from the ice tray to the water reservoir through a coil concentrically disposed in an evaporator. The icemaker can reduce a time required to make ice pieces by lowering a temperature of the water to be supplied to the ice tray, but a structure thereof is complicated.